Adhesive-coated fabric or cord

ABSTRACT

Adhesive-coated tire cord fabric and similar fabric and single end cords for other end uses can be protected from the adverse effects of atmospheric pollutants, prior to the adhesion of such fabrics to rubber, by incorporating N,N&#39;&#39;-ethylene bis-stearamide in the adhesive formulation.

0 United States Patent 1191 1111 3,876,457 Adams Apr. 8, 1975 [54]ADHESIVE-COATED FABRIC OR CQRD 3,443,986 5/1969 Watanabe et a1 156/335 X3,549,481 12/1970 Cesare et a1. 156/335 X [75] Inventor 3 Tysm AdamsLeesvme/ 3,775,150 11/1973 McClary 117/90 x [73] Assigneez Uniroyal,Inc., New York, NY. Primary ExaminerfiRalph Husack [22] Filed: Aug. 2,1973 Attorney, Agent, or Firm-Wililard R. Sprowls, Esq. [21] Appl. No.:385,200

52 us. (:1. 117/13s.s N; 117/72; 117/76 T; [571 ABSTRACT 117/90;Adhesive-coated tire cord fabric and similar fabric [5]] Em B32b25/l0B3Zb 27/3'6 and single end cords for other end uses can be pro- [58]Fieid 6/335, 1 17/90 72 76 T tected from the adverse effects ofatmospheric pollutl i'g' F 138 g N 1 260/29 ants, prior to the adhesionof such fabrics to rubber, by incorporating N,N-ethy1ene bis-stearamidein the [56] References Cited adhesive formulation.

UNITED STATES PATENTS 4 Claims N0 Drawings $135,624 6/1964 Nakane et a]156/335 X ADHESIVE-COATED FABRTC R CORD This invention relates to theprotection of adhesivecoated tire cord, other fabrics, and single endcords. which are subsequently, after storage and/or shipment, to beadhered to rubber layers, from the adverse effects of atmosphericpollutants. It has been found that such fabrics and cords, afterexposure to high levels of atmospheric pollutants present at normal tohigh temperatures and with a high incidence of UV light, demonstratelittle or no adhesion to rubber layers in the construction of tires andother end products.

A patent to Watanabe et al., US. Pat. No. 3,443,986, proposes theinclusion of certain waxes in adhesion formulations to improve theadhesive strength of fibrous materials coated therewith. However, theformulations of this patent do not provide the answer to the problemencountered by the applicant.

Conventional adhesive dip formulations for application to fabric madefrom polyamide, polyester or rayon cord, which is subsequently to beadhered to shaped rubber articles prior to the vulcanization thereof,comprise a dip of a resorcinol-formaldehyde condensate and a latex of avinyl pyridine-butadiene-styrene terpolymer or of a butadiene-styrenecopolymer. It has been found that the effects of atmospheric pollutants,as referred to above, can be overcome by the incorporation of from about1 to about weight percent, based on the dry rubber solids content of thedip, of N,N- ethylene bis-stearamide. This bis-stearamide is a waxymaterial having a melting point of 288 to 293F.

This invention will be described primarily in terms of the preparationof polyamide, polyester or rayon tire cord fabric for incorporation intoshaped rubber tire carcasses with good adhesion. The following examplesare given to demonstrate the application of the invention. It isunderstood that the invention is equally applicable to adhesive-coatedfabric and single end cords intended for other uses.

EXAMPLE 1 This example illustrates the application of the novel additiveof the present invention to protect polyester tire cord from the adverseeffects of atmospheric pollutants, prior to adhesion of such fabrics torubber.

Twisted 3440 denier, polyester (polyethylene terephthalate) tire cordconsisting of 3 ply cord (in which each ply has 9.2 Z turns in thesingles and 9.2 S turns in the plying operation) is run through a firstdip having the following composition described in US. Pat. No.3,307,966.

Composition Dip One 1. 22.0g phenol blocked MD] (Hylene MP DuPont) 2.1.5g Aerosol O.T. (dioctyl sodium sulfosuccinate) 3. 9.0g Epon 812 (anepoxide) 4. 1200g Water The total solids on the cord after this firstdip treatment is 0.5-1 .5% (dry weight based upon the weight of thecord).

The cord is then cured for 40 seconds at 445F while applying 2.0%stretch. The cord is then run through a second dip (RFL dip) having thefollowing compositron:

Composition Dip Two 1. 100g Vinyl pyridine latex (40% solids consistingof butadiene 15% vinylpyridine 15% styrene terpolymer (Pyratex) 2. 2.5gAmmonium hydroxide 3. 9.0g Resorcinol-formaldehyde condensation product(Koppers Penacolite 2170") 4. 4.5g Formalin (37%) diluted with water to20% solids 5. N,N-Ethylene-bis-stearamide 5 parts wax solids to lOOparts dry rubber solids.

Modified resorcinolformaldehyde condensation products can also besubstituted, e.g., those in which another dihydric phenol is used or inwhich a third reactive component is included.

In general, the additive of this invention was made into a slurry bymixing various proportions of the additive and water with theappropriate dispersing system. The amount of additive used and found tobe effective amounts to about 1 to 10 weight percent, based on the driedrubber.

The cord is then dried and cured at 390F for seconds. The percent solidsof RFL picked up on the cord is 2.5 to 4.5% dry weight based upon theweight of the cord. Adhesion results are obtained using the followingtest method which is also described in US. Pat. No. 3,549,481, thecontents of which are hereby incorporated by reference herein.

A desirable procedure for storing and shipping the rolls of adhesivedipped tire cord fabric is to wrap each one in a polyethylene bag, drawa vacuum on the bag and tape the previously open end of the bag.Additional packing may be desirable prior to shipment but, with thistreatment, there is no problem concerning atmospheric pollutants andU.V. light. It is only after the roll of tire cord fabric is withdrawnfrom the polyethylene bag in a badly polluted atmosphere that theproblem solved by this invention is encountered.

The atmospheric pollutants which cause the most trouble for fabricadhesive coatings are the oxides of nitrogen and ozone. These areparticularly detrimental in the presence of high temperature, lowhumidity and exposure to light, the ultraviolet rays being mostdamaging. Consequently, for testing purposes, a six foot by six footroom was equipped with apparatus necessary to provide the followingconditions:

l0 to 25 parts/hundred million 8 to l5 parts/hundred million TemperatureRelative Humidity Ozone Concentration Nitrogen Dioxide Using thislaboratory accelerated testing procedure, the use of the additive ofthis invention increases the resistance to adhesion loss by at least afactor of three in time. This is of vital importance since the fabricmust retain good adhesion throughout all operations in conversion into atire, a conveyor belt, etc. In general, those samples which retain anadhesion appearance of 4.0 or greater after one hour in this test havebeen found to process without problems under factory conditions.

Treated polyester cords are placed in parallel arrangement with 24 endsto the inch. Two pieces of 3 inch X 4 inch backing stock (a rubbermaterial having a light weight reinforcing fabric in it) are pressedonto the cords by hand with the cord running parallel to the 3 inchside. The two pieces of backing stock are placed so that they coverdifferent portions of the cords and are approximately one inch apart.The cord is then trimmed even around the edges of the backing stock. Thecord side of the backing stock is then pressed by hand onto an adhesionstock. A typical formulation would be a 35/45/20 blend of naturalrubber, styrenebutadiene rubber and cis-butadiene rubber tire skim stockcontaining 50 parts of carbon black, -l.5 parts of stearic acid, 25parts of reclaimed rubber, 10 parts of zinc oxide, 1 part ofantioxidant, 5 parts of pine tar, 1 part of mercaptobenzothiazole, 0.1part of diphenylguanidine and 3.2 parts of sulfur. Care is taken not totouch the cord or the adhesion surface of the backing stock or theadhesion stock. The articles formed are trimmed and cut in half. A 1inch X 4 inch aluminum foil or Holland Cloth separator is placed on theexposed surface of the adhesion stock on one of the specimen halves,with the separator being aligned along one 4 inch edge. The specimenhalves are laminated together so that adhesion stock contacts adhesionstock except in the area where the separator is present.

The assembly is placed in a press and cured for 6 minutes at 350F platentemperature and 200 psi pressure.

The resultant article is cut into four 1 inch X 3 inch strips and thetwo end strips are discarded.

The separator is removed from the end of the remaining middle strips,the two end portions (referred to as tabs) are spread apart andmaintained in that condition and the strips are placed in an lnstronoven at 250F for 30 minutes. Subsequently the tabs of each article areplaced in the jaws of an lnstron Tester, and the jaws of the tester areseparated at a rate of 5 inches per minute and a chart speed of 1.5inches per minute. Sufficient force in the tester is obtained toseparate the article along its length. The separated surfaces are thenexamined to see how much of the cord has become visible due to strippingof the rubber from the cord. This is recorded according to the followingscale:

Rating 5 1007: Rubber Failure No Cord Visible 4 75% Rubber Failure 25%Cord Visible 3 50% Rubber Failure 50% Cord Visible 2 25% Rubber Failure75% Cord Visible I Table l Appearance/Lbs. Pull Mins.* 60 Mins.* I80Mins.*

No Additive 5.0/35 4.0/30.0 l.5/28.5 5 Parts Additive 5.0/36.6 5.0/38.05.0/4l.0 7% Parts Additive 5.0/32.5 5.0/37.0 5.0/37.5 10 Parts Additive5.0/32.5 5.0/34.5 50/355 Example 2 This example illustrates theapplication of the additive of the present invention in a single dipsystem to protect polyester tire cord from the adverse effects ofatmospheric pollutants.

A twisted 3 ply, 3440 denier, polyester tire cord as described inExample 1 is run through a single dip system (l-l-7) described by [C]literature and in the British Polymer Journal [V0]. 3, p. 58 (1971)].Briefly this dip system consists of an RFL (similar to that described inExample I) with a special resin additive prepared from p-chlorophenol,resorcinol and formaldehyde. The cord is treated as described in ExampleI with the exception that 460F is required in the first oven instead of445F. Normally a dry weight ratio of 20g special resin to 40g RFLportion is employed.

Total solids on the cord is 4.5-5%.

Table II Appearance/Lbs. Pull Ozone PPl- M 0 Mins. 60 Mins.

Without additive 10 49/290 3.0/26.0 With additive* l0 4.9/30.5 4.5/29.5

10 parts by weight based on I00 parts dry ruhhcr solids (Latex).

Example 3 Table Ill Nylon 6.6 with N,N'-Ethylene-Bis-StearamideAppearance/Lbs. Full 0 Mins.* 15 Mins.* 30 Mins.

No Additive 4.9/34.5 l.5/38.0 l.0/l8.0 1 Part Additive 4.9/35.0 4.0/36.04.0/34.0 5 Parts Additive 4.8/39.5 4.7/38.5 4.5/3l.5 [0 Parts Additive4.8/34.5 4.7/37.5 4.5/29.5

Note: Amounts of additives are based on dry rubber solids (Latex)Exposure l0 PPHM ozone. l0 PPHM oxides of nitrogen.

Example 4 Fiber B is an aromatic polyamide (condensation polymer ofp-phenylenediamine and terephthalic acid) developed by DuPont. Twisted4570 denier Fiber B 1500/ 3 ply) tire cord is treated similarly topolyethylene terephthalate described in Example l.

Table IV Appearance/Lbs. Pull 0 Mins.* Mins.

Without Additive 5.0/35.0 l.5/20.0 With Additive" 50/340 49/ 34.0

Note: Amounts of additives are based on dry rubber solids. Minutes ofexposure at 10 PPHM Ozone and 10 PPHM Oxides of nitrogen.

Exposure 10 PPHM ozone. l0 PPHM oxides of nitrogen. l0 pans/I00 partsdry rubber.

Example This example illustrates the use ofthe additive of the presentinvention 'with rayon tire cord. This 3300 denier cord is processed thesame as that described for nylon 6,6 in Example 3 or withstyrenebutadiene rubbery copolymer (40% solids) substituted for thevinyl pyridine terpolymer.

Exposure l0 PPHM ozone. l0 PPHM oxides of nitrogen. l0 partsadditive/I00 parts dr rubber.

The foregoing examples establish the excellent re sults which areobtained by the use of the additive of this invention.

Example 6 Cetyl stearate has been set forth as a desirable additive inUS. Pat. No. 3,443,986. This additive was compared toN,N'-ethylene-bis-stearamide at PPHM ozone with polyester cord. Theresults summarized in Table VI reveal the unsatisfactory nature of cetylstearate as an adhesive additive for the purposes of this invention.

Table VII-Continued Royalac 136 (proprietary accelerator like adithiocarbamate) Butyraldehyde-aniline condensation product (UniroyalBeutene. DuPont Antox) p-Chlorophenol-formaldehyderesorcinol prcpolymer(lCls Pexul) Triallylcyanurate-formaldehydercsorcinol prepolymer (lCl'sN 3) Phenyl-B-naphthylamine (DuPont Neozone D D Special)Phenyl-a-naphthylamine (DuPont Neozone A) 2.4-dihydroxy benzophcnone(DuPont Rylex H) 4-dodecyloxy-2-hydroxy bcnzophenone (DuPont Rylex D)Diaryl phcnylenediamines (DuPont Akroflex DAZ. Uniroyal .IZF)

. Dialkylthioureas (Pennzone Methyl l-(butylcarbamoyl) 2-bcnzimidazolecarbamatc (DuPont Benlatc) Nickel dibutyl dithiocarbamate (DuPont NBC)Diphenyl propylenediaminc (C.

P. Hall Hallcolitc L) 6-Ethoxyl .2-dihydro-2.2.4-

trimethyl quinoline (Monsanto Santoflex AW) pentyl )-p-phenylenediamineSodium diethyl dithiocarbamate Dibutyl tin bis dibutyl dithiocarbamateElemental sulfur The next set of waxes (22-33) are generally C l 8-C30Table VI lnitial Adhesion 30 Mins. Exposure* l Hour Exposure App. Lbs.Pull App. Lbs. Pull App. Lbs. Pull No additive 5.0 33.5 4.0 28.5 L5 25.05'7: N.N'-ethylene 5.0 32.5 5.0 34.0 5.0 37.0

bis-stearamide** 5'71 cetyl stearate*** 5.0 33.0 l.2 23.5 l.0 26.5 l07rcetyl stearate*** 5.0 33.0 l.0 25.5 l.0 25.5

Exposure )0 PPHM ozone. l0 PPHM oxides of nitrogen. "Based on dry rubbercontent of rubber latex. Dispersion in water.

Example 7 Table VI] presents a list of materials which wereunsatisfactory for the purposes of this invention with polyester cordunder the conditions described in Example 1. Most of the materials weretried at 2, 4, 6, 8 and 10 percent levels based on dry rubber solids(latex); the coated cords were tested in the exposure test described inExample 1 at 25 PPHM ozone.

Table Vll Identification Remarks No resistance to exposure (1.0appearance after 30 minutes exposure) based mixtures with highhydrocarbon content which were previously advanced as additives in US.Pat. No.

ESSO Household Paraffin Wax Nopco Corax Wax (paraffin wax) Histowax(paraffin wax) Baker C astorwax (glyceryl tri( l Z-hydroxystearate)Baker Dispersion 33 (dispersion of Baker Castorwax) Socony-MobilMobilsir (paraffin wax) Cincinnati Milacron Advawax 440 (bis-amidepolymer) Acrawax (amide derived from fatty acid) Acrowax B (amidederived from tri-glyceride) Acrawax HM (amide) Glyconol (isopropylbisstearamide) Glycolube VL (ethylene bis-oleamide No resistance toexposure H lncompatibledwith Adhesive Incompatible with Adhesive ingeneral, the final weight of adhesive coating solids on the fabrics ofthis invention is on the order of 3l0 weight percent, the amount of theadditive of this invention, based on the fabric weight, being on theorder of 1.0 weight percent, although this amount can range as low as0.l weight percent.

A valuable method of providing protection from atmospheric pollutantsfor adhesive-coated tire cord and other fabrics has been presented inthe foregoing description and is covered by the following claims.

Having thus described my invention, what I claim and desire to protectby letters patent is:

l. A fabric or single end cord made from a polyamide, polyester, orrayon cord and coated with 3 to 10 weight percent, based on the fabricweight, of a dried adhesive comprising: l) a resorcinol-formaldehydecondensate and (2) a vinyl pyridine-butadiene-styrene rubbery terpolymeror butadiene-styrene rubber copolymer composition, and (3) N,N'-ethylenebisstearamide, said coated fabric or single end cord having thecharacteristic of better retention of adhesion after exposure toatmospheric pollutants and U.V. light.

2. The product of claim 1 wherein the polyamide fabric or cord is nylon6,6.

3. The product of claim 1 wherein the polyamide fabric or cord is FiberB.

4. The product of claim 1 wherein the polyester fabric or cord ispolyethylene terephthalate.

1. A FABRIC OR SINGLE END CORD MADE FROM A POLYAMIDE, POLYESTER, ORRAYON CORD AND COATED WITH 3 TO 10 WEIGHT PERCENT, BASED ON THE FABRICWEIGHT, OF A DRIED ADHESIVE COMPRISING:(1) A RESORCINOL-FORMALDEHYDECONDENSATE AND (2) A VINYL PYRIDINE-BUTADIENE-STYRENE RUBBERY TERPOLYMEROR BUTADIENESTYRENE RUBBER COPOLYMER COMPOSITION, AND (3) N,N''ETHYLENEBIS-STEARAMIDE, SAID COATED FABRIC OR SINGLE END CORD HAVING THECHARACTERISTIC OF BETTER RETENTION OF ADHESION AFTER EXPOSURE TOATMOSPHERIC POLLUTANTS AND U,V, LIGHT.
 2. The product of claim 1 whereinthe polyamide fabric or cord is nylon 6,6.
 3. The product of claim 1wherein the polyamide fabric or cord is Fiber B.
 4. The product of claim1 wherein the polyester fabric or cord is polyethylene terephthalate.